XIV TABLE OF CONTENTS. 



CHAPTER XII. 

 Latieiferous Tubes. 



PAGE 



Sect. 131 432 



CHAPTER XIII. 



Arrangement of the Intereellnlar Spaces. 



Sect. 132. Spaces containing Air 44° 



„ 133. Intercellular Secretory Reservoirs 44° 



SECOND SECTION. SECONDARY CHANGES. 



CHAPTER XIV. 



Secondary Growth in Thickness of I^ormal Dicotyledonous Stems 



and Boots. 



I. Cambium. Secondary Thickening. 



Sect. 134. Origin of the Cambium in the Stem. Intermediate Bundles . . . 454 



„ 135. Subdivisions of the Secondary Thickening in the Stem .... 458 



„ 136. Cambium and young Secondary Growth 461 



„ 137. General Arrangement of the Secondary Elements as seen in Transverse 



Section 469 



„ 138. Their Longitudinal Course 470 



139. Cambium and Secondary Thickening of Roots 473 



II. The Wood. 



I. Distribution and Form of the Zones of Secondary Growth. 



„ 140 475 



2. The Tissues of the Secondary Wood. 



141. Synopsis 478 



142. Trachese 478 



143. Woody Fibres 481 



144. Cells . . 483 



145. Crystal-sacs. Latieiferous Tubes 487 



Critical Note 487 



3. Distribution of the Tissues in the Wood. 



146. General Considerations 488 



a. Medullary Rays and Medullary Spots. 



147. Medullary Rays 480 



148. Medullary Spots 402 



